Abstract

Variations in male and female mating behavior in the cockroach, Nauphoeta cinerea (Olivier 1789), reflect differences in male produced pheromones and sexual selection. Mating is nonrandom in this cockroach: males form social hierarchies that influence access to reproductive females and females discriminate among males prior to mating. These social discriminations result in male-male competition and female mate choice, the behavioral mechanisms of sexual selection. Male-male competition for mates incorporates both intrasexual agonism and variation in male behavior during courtship. Further, courtship variation reflects differences in male social status. Female mate choice also occurs during courtship; the temporal structure of interactions depends on the attractiveness of the male. Attractiveness of socially naive males can be used to predict future social status. Thus, dominant males enjoy a mating advantage due to both male-male competition and female mate choice. - 2 different pheromonal signals appear to be involved in communication of individual differences. In intersexual interactions, behavioral variation in both sexes prior to contact reflects perceived differences in the male producedvolatile (sex) pheromone. In contrast, variation in both male and female behavior after contact reflects differences in the male produced contact pheromone. In addition, some of the differences in both male and female behavior are in part due to genetic variation among individuals. Phenotypic and genetic correlations support the hypothesis that different behaviors reflect responses to distinct pheromones. These results support the hypothesis that sexual selection appears to have been an important evolutionary influence on both behavior and the contact pheromone in N. cinerea.